Study type: Therapeutical study (experimental study)

Effect of weak, interrupted sinusoidal low frequency magnetic field on neural regeneration in rats: functional evaluation med. app.

By: Bervar M
Published in: Bioelectromagnetics 2005; 26 (5): 351-356
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Aim of study (acc. to author)

To study the effect of weak, interrupted sinusoidal low frequency magnetic field stimulation on regeneration of the rat sciatic nerve.

Background/further details

60 rats were used: 24 animals underwent unilateral sciatic nerve transection injury and immediate surgical nerve repair, 24 animals underwent unilateral sciatic nerve crush injury, and the remaining 12 animals underwent a sham surgery. Half of the rats (n = 12) with either sciatic nerve lesion were randomly chosen and irradiated for three weeks post-injury. The other half of the rats (n = 12) and six rats with sham surgery were used for two separate controls.
Functional recovery was followed for six weeks for the crush injuries and seven and a half months for the transection injuries.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: intermittent (1.4 s/0.8 on/off period); this pattern was applied for 4 h daily for 3 weeks

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration intermittent (1.4 s/0.8 on/off period); this pattern was applied for 4 h daily for 3 weeks
Exposure setup
Exposure source
Chamber cage placed within the coils system
Setup rats placed in a round, non-conductive plastic cage (28 cm in diameter) and were free to move in it; the longitudinal rat`s axis was normally perpendicular to the magnetic field.
Sham exposure A sham exposure was conducted.
Additional info The generator producing the sine waves was interupted with a frequency of 0.45 Hz, hence creating an active and inactive period of 1.4 s and 0.8 s, respectively.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 500 µT unspecified measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The positive effects of the stimulation on the functional recovery patterns in exposed animals and both injury models were statistically confirmed. Significant differences between exposed and control rats were revealed early at the start of functional recovery and later on from the points adjacent to the beginning of the functional recovery plateau until the end of observation.
These differences probably reflect the interrupted sinusoidal low frequency magnetic field systemic effect on the neuron cell bodies and increased (and more efficient) reinnervation of the periphery.

Study character:

Study funded by

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